Big Dobs - are their days numbered?

[pipnina]

How big counts as big? 16" is certainly larger than most people would want to put up with, unless it is going to live on a concrete slab in the garden!

My 10" is about as big as I think I could transport and set up reasonably. Maybe if I was desperate for more size 12" could fit... But the tube alone for the 10" is already 14KG let alone the base. And it takes up nearly the full length of the car boot.

I will say though, the difference in view quality between the 5" newt and the 10" newt I have owned was no comparison. The 10" wins hands down. Outside of maybe exceptionally large objects? But then my 10" captured andromeda very nicely (bortle 4).

[John]

One of my most memorable moments in astronomy was delivered by a 20 inch dobsonian at a reasonably dark site in Herefordshire - where the SGL star parties used to be held.

I got to look at Messier 51 and Messier 13 (the owner asked me what I would like to see) and the views were jaw dropping 😲

Although the level of detail on view could probably be replicated by one of todays portable "smart" telescopes, the sheer thrill of putting my eye to the eyepiece of the big dob and seeing these famous objects in their full splendour apparently laid out in front of me was something that I will never forget. It's actually quite an intimate thing - just you and the Universe for a minute or two 😁

[NGC 1502]

I had a similar moment to the above.   Several years ago I was at Kelling Heath star party in north Norfolk. During the day I had seen Liverpool Astronomy Society’s 30” Dob, it had attracted a great deal of attention😁. The secondary mirror was 8” !!!

That night was clear, so myself and clubmate Jim went over to the 30” hoping to get a peek……the 30” was aimed at M33 the well known face on spiral galaxy in Triangulum.  Those in charge of the scope were allowing folks to have a look, the few minutes I waited seemed like forever……

My turn came….obvious spiral arms…..a moment like no other for me……never ever to be forgotten.  That view beats any image no matter how stunningly detailed.   It’s that direct connection across the void of space, those photons of light from so far away hitting my retina and perceived by my brain and consciousness…..just totally fabulous.

Diehard visual observers will understand.   Not knocking those fabulous images, but for me the visual view will always be king.

Ed.

 

Edited May 21 by NGC 1502
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[paulastro]

6 hours ago, NGC 1502 said:

I had a similar moment to the above.   Several years ago I was at Kelling Heath star party in north Norfolk. During the day I had seen Liverpool Astronomy Society’s 30” Dob, it had attracted a great deal of attention😁. The secondary mirror was 8” !!!

That night was clear, so myself and clubmate Jim went over to the 30” hoping to get a peek……the 30” was aimed at M33 the well known face on spiral galaxy in Triangulum.  Those in charge of the scope were allowing folks to have a look, the few minutes I waited seemed like forever……

My turn came….obvious spiral arms…..a moment like no other for me……never ever to be forgotten.  That view beats any image no matter how stunningly detailed.   It’s that direct connection across the void of space, those photons of light from so far away hitting my retina and perceived by my brain and consciousness…..just totally fabulous.

Diehard visual observers will understand.   Not knocking those fabulous images, but for me the visual view will always be king.

Ed.

 

I looked at the Veil through that 30inch at Kelling, it was a staggering view.  It looked like an oil painting, rich in detail and colour.  Really in your face.  We were close to the Liverpool lads pitch so had a few views throughout the week.  Easily the best deep sky views I've had.

Edited May 21 by paulastro

[Richard N]

16 hours ago, Xilman said:

Martin uses an equatorial platform and a video camera. I claim that for some work the equatorial platform is not essential, albeit desirable, 

 

There are some who might suggest that a Newtonian scope on an equatorial mount is not a Dob at all. And I would suggest that because something can be done doesn’t mean it’s a good option for most. 

[Stu]

28 minutes ago, Richard N said:

There are some who might suggest that a Newtonian scope on an equatorial mount is not a Dob at all. And I would suggest that because something can be done doesn’t mean it’s a good option for most. 

Ah, but as in this case, a dob on an Equatorial Platform (not mount) is still a dob!

[Giles_B]

17 minutes ago, Stu said:

Ah, but as in this case, a dob on an Equatorial Platform (not mount) is still a dob!

I'm also intrigued by the option of using an EQ platform for imaging having struggled (and failed) for about two hours last night to get my 10" newt plus an imaging train balance on an EQ6! I think I'll be trying this option come planet season.

[Stu]

55 minutes ago, Giles_B said:

I'm also intrigued by the option of using an EQ platform for imaging having struggled (and failed) for about two hours last night to get my 10" newt plus an imaging train balance on an EQ6! I think I'll be trying this option come planet season.

Should work very well, and much more easily for planetary and is perfectly doable for DSO although I haven’t tried that. I think @PeterStudz is our resident expert on this topic 👍

[scarp15]

I do not think that their days are numbered, yet are certainly niche. More applicable if you happen to live somewhere remote with the benefit of occasional clear and dark skies, or else are committed to annual star camps where there might be fortuitous clear sky conditions. Then also if able to venture out to travel to a dependable and safe location from home; in which case there is nothing better to have. 

A large aperture dob may not get the use compared to other alternative instruments and determined by whether collapsible or not, can be a cumbersome object to have around the house. Also with the recent passing of dobsonian maker David Lukehurst, there are less options for an aspiring UK large dobsonian owner, unless able to have the means and dedication to project build their own (in which of course the forum is a good supportive and advisory place to be). 

Having been an owner of a 14" dobsonian, the excitement and appeal in exploring at dark sky locations is unsurpassable and is an indicator as to what a truly large dobsonian at 18+ would be capable of revealing.   

 

[Paz]

I think big dobs are at the more specialist end of the spectrum, you have to be fairly dedicated to own one, and home made dobs all the more so.

I still have a VX14 but it has seen less use the last few years for health reasons and then cloud reasons. It's not easy to want to set it up when I might only get 5 minutes (or zero minutes) at the eyepiece before the clouds roll in.

[Second Time Around]

I suspect that these days most big Dobs bought in the UK are used in an observatory, like the excellent 20 inch I looked through at Eddington Lodge holiday cottages near Bude.

I don't have a garden suitable for anything bigger than a 10 inch f/4.8, which is the biggest I can carry outside.  It's also small enough to go on the back seat of most cars.

Rather than the expense of a big Dob I've spent the extra money on a night vision device. 

On many DSOs, especially globulars and gaseous nebulae, it's like having a scope 2x or even 3x as big.  My OVNI-M is about the same size as many eyepieces, and can in fact be used as an eyepiece on any scope. 

It can can also be used with many camera lenses for handheld use - my favourite is a 75mm f/1.8 that gives 3x magnification.  With an h-alpha filter this gives great views for instance of the North American Nebula, the Rosette Nebula and Barnard's Loop in my Bortle 4/5 sky.  It can also be used on its own as a 1x monocular with a 40 degree FOV where it shows hugely more stars than the naked eye.

[bingevader]

On 20/05/2024 at 19:52, Xilman said:

I note the smiling face, but do you really have that little imagination?  Renting a van is really not very expensive, especially in comparison with the cost of a fair-sized telescope.

I'll assume the smiley face is missing from that remark!

If the 'scope had been available, we'd have found a way (and it certainly wouldn't have involved renting a van!).

[jjohnson3803]

I'd wager two impediments are storage and transportation for those without an observatory of some kind.

 

[Paz]

2 hours ago, Second Time Around said:

Rather than the expense of a big Dob I've spent the extra money on a night vision device. 

I have an eye on this as a potential future option in the long run.